1. Field of the Invention
The present invention relates to a catalyst of a fuel cell, and a membrane-electrode assembly and a fuel cell system including the catalyst. More particularly, the present invention relates to a catalyst that has a high catalyst utility, and facilitates a highly efficient and high power fuel cell, and a membrane-electrode assembly and a fuel cell system including the catalyst.
2. Description of the Related Art
A fuel cell is a power generation system for producing electrical energy through an electrochemical redox reaction of an oxidant and hydrogen in a hydrocarbon-based material, such as methanol, ethanol, or natural gas. Such a fuel cell is a clean energy source that may replace fossil fuels. It includes a stack composed of unit cells, and produces various ranges of power. Since it has four to ten times higher energy density than a small lithium battery, it has been highlighted as a small portable power source.
Representative exemplary fuel cells include a Polymer Electrolyte Membrane Fuel Cell (PEMFC) and a Direct Oxidation Fuel Cell (DOFC). The DOFC includes a direct methanol fuel cell that uses methanol as a fuel.
The polymer electrolyte fuel cell has an advantage of high energy density, but it also has problems in the need to carefully handle hydrogen gas and the requirement of accessory facilities such as a fuel reforming processor for reforming methane or methanol, natural gas, and the like in order to produce hydrogen as the fuel gas.
On the contrary, a DOFC has a lower energy density than that of the polymer electrolyte fuel cell, but it has the advantages of easy handling of a fuel, being capable of operating at room temperature due to its low operation temperature, and no need for additional fuel reforming processors.